Synthesis and structural characterization of a diruthenium pentalene complex, [^Cp∗Ru{(^Cp∗Ru)2B6H14}(^Cp∗Ru)]

Abstract : Treatment of nido-[1,2-(Cp*Ru)2(μ-H)2B3H7], 1 with five equivalents of Te powder led to the isolation of diruthenium pentalene analogue [(Cp*Ru) { (Cp*Ru) 2B 6H 14} (RuCp*)] , 2 and a metal indenyl complex [(Cp*Ru) 2B 2H 6C 6H 3(CH 3)], 3. The [(Cp*Ru) 2B 6H 14] fragment in 2 may be considered as a true metal–boron analogue of η 5-η 5-pentalene ligand (C 8H 6) and [(Cp*Ru) B 2H 6C 6H 3(CH 3)] fragment in 3 is an analogue of η 5-indenyl ligand. The solid-state X-ray structures were unambiguously determined by crystallographic analysis of compounds 2 and 3. Further, the density functional theory (DFT) calculations were performed to investigate the bonding and the electronic properties of 2a (Cp analogue of 2). The frontier molecular orbital analysis of both 2a and 2b (Cp analogue of [(Cp*Ru) B 8H 14(RuCp*)]) reveals a lower HOMO–LUMO gap indicating less thermodynamic stability. Graphical Abstract: SYNOPSIS Treatment of nido-[1,2-(Cp∗ Ru)2(μ -H)2B3H7] with Te powder led to the isolation of diruthenium pentalene analogue [(Cp*Ru) { (Cp*Ru) 2B 6H 14} (RuCp*)] and a metal indenyl complex [(Cp*Ru) 2B 2H 6C 6H 3(CH 3)]. [Figure not available: see fulltext.]